feat: setup.py redesign and helpers (#2433)

* feat: setup.py redesign and helpers

* refactor: simpler design with two outputs

* refactor: helper file update and Windows support

* fix: review points from @YannickJadoul

* refactor: fixes to naming and more docs

* feat: more customization points

* feat: add entry point pybind11-config

* refactor: Try Extension-focused method

* refactor: rename alt/inplace to global

* fix: allow usage with git modules, better docs

* feat: global as an extra (@YannickJadoul's suggestion)

* feat: single version location

* fix: remove the requirement that setuptools must be imported first

* fix: some review points from @wjacob

* fix: use .in, add procedure to docs

* refactor: avoid monkeypatch copy

* docs: minor typos corrected

* fix: minor points from @YannickJadoul

* fix: typo on Windows C++ mode

* fix: MSVC 15 update 3+ have c++14 flag

See <https://docs.microsoft.com/en-us/cpp/build/reference/std-specify-language-standard-version?view=vs-2019>

* docs: discuss making SDists by hand

* ci: use pep517.build instead of manual setup.py

* refactor: more comments from @YannickJadoul

* docs: updates from @ktbarrett

* fix: change to newly recommended tool instead of pep517.build

This was intended as a proof of concept; build seems to be the correct replacement.

See https://github.com/pypa/pep517/pull/83

* docs: updates from @wjakob

* refactor: dual version locations

* docs: typo spotted by @wjakob

.pre-commit-config.yaml

@@ -1,6 +1,21 @@
+# To use:
+#
+#     pre-commit run -a
+#
+# Or:
+#
+#     pre-commit install  # (runs every time you commit in git)
+#
+# To update this file:
+#
+#     pre-commit autoupdate
+#
+# See https://github.com/pre-commit/pre-commit
+
 repos:
+# Standard hooks
 - repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v3.1.0
+  rev: v3.2.0
   hooks:
   - id: check-added-large-files
   - id: check-case-conflict
@@ -14,11 +29,21 @@ repos:
   - id: trailing-whitespace
   - id: fix-encoding-pragma
 
+# Black, the code formatter, natively supports pre-commit
+- repo: https://github.com/psf/black
+  rev: 20.8b1
+  hooks:
+  - id: black
+    # Not all Python files are Blacked, yet
+    files: ^(setup.py|pybind11|tests/extra)
+
+# Changes tabs to spaces
 - repo: https://github.com/Lucas-C/pre-commit-hooks
   rev: v1.1.9
   hooks:
   - id: remove-tabs
 
+# Flake8 also supports pre-commit natively (same author)
 - repo: https://gitlab.com/pycqa/flake8
   rev: 3.8.3
   hooks:
@@ -26,6 +51,7 @@ repos:
     additional_dependencies: [flake8-bugbear, pep8-naming]
     exclude: ^(docs/.*|tools/.*)$
 
+# CMake formatting
 - repo: https://github.com/cheshirekow/cmake-format-precommit
   rev: v0.6.11
   hooks:
@@ -34,6 +60,16 @@ repos:
     types: [file]
     files: (\.cmake|CMakeLists.txt)(.in)?$
 
+# Checks the manifest for missing files (native support)
+- repo: https://github.com/mgedmin/check-manifest
+  rev: "0.42"
+  hooks:
+  - id: check-manifest
+    # This is a slow hook, so only run this if --hook-stage manual is passed
+    stages: [manual]
+    additional_dependencies: [cmake, ninja]
+
+# The original pybind11 checks for a few C++ style items
 - repo: local
   hooks:
   - id: disallow-caps